* 12to11.c (XLMain): Initialize timestamp tracking.
* 12to11.man: Document *.useDirectPresentation resource.
* atoms.c (names): Add _NET_WM_PID and _NET_WM_PING.
(XLInitAtoms): Likewise.
* compositor.h (struct _RenderFuncs): Update doc of
cancel_presentation.
(enum _FrameMode): Add ModeNotifyDisablePresent.
(struct _XdgRoleList, struct _XdgWmBase): New structs.
* frame_clock.c (StartFrame): Return if the clock was really
started.
(XLFrameClockStartFrame): Likewise.
(XLInitFrameClock): Move Sync extension initialization to
InitTime.
* picture_renderer.c (struct _PresentCompletionCallback)
(struct _PictureTarget, InitSynchronizedPresentation)
(InitRenderFuncs, TargetFromDrawable, DestroyRenderTarget)
(PresentToWindow, CancelPresentationCallback, AddRenderFlag)
(HandlePresentCompleteNotify): Link structure on target. When
synchronized presentation is enabled, use the approriate msc to
present, and record the last known msc.
* run.c (HandleOneXEvent): Handle timestamp events.
* subcompositor.c (SubcompositorUpdate): Note frame with
ModeNotifyDisablePresent.
(FindSystemCounter, ValueToScalar, ScalarToValue, StartAlarms)
(HandleAlarmNotify, HandleOneXEventForTime, InitTime): New
functions.
* xdg_surface.c (struct _XdgRole): New fields `link' and
`wm_base'.
(struct _PingEvent): New structure.
(ReleaseBacking): Release all ping events.
(NoteFrame, WriteRedirectProperty): Allow unredirection under
some circumstances.
(XLGetXdgSurface): Attach wm base.
(XLXdgRoleHandlePing, ReplyPingEvent, XLXdgRoleReplyPing): New
function.
* xdg_toplevel.c (GetClientMachine): New function.
(WriteCredentialProperties): New function.
(Attach): Write credential properties.
(ReplyToPing): New function.
(XLHandleXEventForXdgToplevels): Handle ping events.
* xdg_wm.c (Pong): Reply to ping events once pong is received
from the client.
(HandleResourceDestroy): Detach all surfaces and run their ping
events.
(HandleBind): Allocate memory for XdgWmBase.
(XLXdgWmBaseSendPing): New function.
